Combining P and S rays for bright stereoscopic projection

Abstract

A multiple path stereoscopic projection system is disclosed. The system comprises a polarizing splitting element configured to receive image light energy and split the image light energy received into a primary path and a secondary path, a reflector in the secondary path, and a polarization modulator or polarization modulator arrangement positioned in the primary path and configured to modulate the primary path of light energy. A polarization modulator may be included within the secondary path, a retarder may be used, and optional devices that may be successfully employed in the system include elements to substantially optically superimpose light energy transmission between paths and cleanup polarizers. The projection system can enhance the brightness of stereoscopic images perceived by a viewer. Static polarizer dual projection implementations free of polarization modulators are also provided.

1. Apparatus for projecting stereoscopic images, comprising:
 a first polarizing splitting element configured to receive first image light energy and split the first image light energy received along a first primary path and along a first secondary path; 
 a first reflector configured to receive one of first primary path of light energy and first secondary path of light energy and to reflect the one of first primary path of light energy and first secondary path of light energy toward a surface; 
 a first rotator configured to receive one of first primary path of light energy and first secondary path of light energy and to rotate the one of first primary path of light energy and first secondary path of light energy; 
 a second polarizing splitting element configured to receive second image light energy and split the second image light energy received along a second primary path and along a second secondary path; 
 a second reflector configured to receive one of second primary path of light energy and second secondary path of light energy and to reflect the one of second primary path of light energy and second secondary path of light energy toward a surface; and 
 a second rotator configured to receive one of second primary path of light energy and second secondary path of light energy and to rotate the one of second primary path of light energy and second secondary path of light energy. 
 
     
     
       2. The apparatus of  claim 1 , wherein the first and second rotators are configured to rotate the one of first primary path of light energy and first secondary path of light energy and the one of second primary path of light energy and second secondary path of light energy by 90 degrees. 
     
     
       3. The apparatus of  claim 1 , wherein the first rotator is positioned between the first polarizing splitting element and the first reflector. 
     
     
       4. The apparatus of  claim 1 , wherein the second rotator is positioned between the second polarizing splitting element and the second reflector. 
     
     
       5. The apparatus of  claim 1 , wherein the first rotator is positioned between the first reflector and the surface. 
     
     
       6. The apparatus of  claim 1 , wherein the second rotator is positioned between the second reflector and the surface. 
     
     
       7. The apparatus of  claim 1 , wherein the first rotator is positioned between the first polarizing splitting element and the surface. 
     
     
       8. The apparatus of  claim 1 , wherein the second rotator is positioned between the second polarizing splitting element and the surface. 
     
     
       9. The apparatus of  claim 1 , further comprising a cleanup polarizer positioned in one of the first primary path of light energy, the second primary path of light energy, the first secondary path of light energy, and the second secondary path of light energy. 
     
     
       10. The apparatus of  claim 1 , further comprising cleanup polarizers positioned in each of the first primary path of light energy, the second primary path of light energy, the first secondary path of light energy, and the second secondary path of light energy. 
     
     
       11. The apparatus of  claim 1 , wherein the surface comprises a projection screen. 
     
     
       12. The apparatus of  claim 1 , wherein the polarizing splitting element comprises one from a group comprising:
 a polarizing beamsplitter; 
 a wire grid polarizer; and 
 a MacNeille prism. 
 
     
     
       13. The apparatus of  claim 1 , further comprising a first path element arrangement and a second path element arrangement configured to substantially optically superimpose light energy transmission between the first primary path of light energy, the second primary path of light energy, the first secondary path of light energy, and the second secondary path of light energy. 
     
     
       14. The apparatus of  claim 13 , wherein the first and second path element arrangements comprise:
 a plurality of reflective surfaces; and 
 a retarder. 
 
     
     
       15. The apparatus of  claim 1 , further comprising:
 a first primary path retarder positioned in the first primary path of light energy at an output portion of the first primary path of light energy; 
 a first secondary path retarder positioned in the first secondary path of light energy at an output portion of the first secondary path of light energy; 
 a second primary path retarder positioned in the second primary path of light energy at an output portion of the second primary path of light energy; and 
 a second secondary path retarder positioned in the second secondary path of light energy at an output portion of the second secondary path of light energy. 
 
     
     
       16. The apparatus of  claim 15 , wherein the first primary path retarder comprises a quarter left retarder, and wherein the first secondary path retarder comprises a quarter right retarder, and wherein the second primary path retarder comprises a quarter left retarder, and wherein the second secondary path retarder comprises a quarter right retarder. 
     
     
       17. The apparatus of  claim 1 , further comprising:
 a first projection lens receiving the first image light energy from a first imaging surface and transmitting the first image light energy toward the first splitting element; and 
 a second projection lens receiving the second image light energy from a second imaging surface and transmitting the second image light energy toward the second splitting element. 
 
     
     
       18. A method of projecting stereoscopic images, comprising:
 receiving first image light energy; 
 splitting the first image light energy received along a first primary path and along a first secondary path; 
 receiving the first secondary path of light energy and directing the first secondary path of light energy toward a surface; 
 receiving one of the first primary path of light energy and first secondary path of light energy and rotating the one of first primary path of light energy and first secondary path of light energy; 
 receiving second image light energy; 
 splitting the second image light energy received along a second primary path and along a second secondary path; 
 receiving second secondary path light energy and directing second secondary path light energy toward a surface; and 
 receiving one of the second primary path of light energy and second secondary path of light energy and rotating the one of second primary path of light energy and second secondary path of light energy. 
 
     
     
       19. The method of  claim 18 , further comprising rotating the one of first primary path of light energy and first secondary path of light energy, and the one of second primary path of light energy and second secondary path of light energy, by 90 degrees. 
     
     
       20. The method of  claim 18 , further comprising:
 rotating the first primary path of light energy at an output portion of the first primary path of light energy using a quarter left rotator; 
 rotating the first secondary path of light energy at an output portion of the first secondary path of light energy using a quarter right retarder; 
 rotating the second primary path of light energy at an output portion of the second primary path of light energy using a quarter left retarder; and 
 rotating the second secondary path of light energy at an output portion of the second secondary path of light energy using a quarter right retarder.